分层填料旋转床气相流场的CFD模拟研究

CFD simulation of gas flow in rotating packed bed with split packing

分层填料旋转床(SP-RPB)是一种新型高效的化工过程强化设备,对气相阻力控制的吸收、精馏等传质过程有明显的强化作用。文中采用计算流体力学方法(CFD)对该结构旋转床内的气相流场进行了模拟研究,分析了流体流速、转子转速及填料转动形式对SP-RPB内部压力场、速度场和湍动能分布的影响规律。计算使用RNG k-ε湍流模型和SIMPLE算法,填料层用多孔介质(Porous Media)模型,模拟结果与实验数据吻合良好。结果表明:SP-RPB内气相压降主要产生在填料区,切向速度远大于径向速度,流场以旋转场为主,湍动程度高于普通的旋转填料床,且湍动能沿径向的分布更为均匀,表明分层填料旋转床在强化气相传质方面比普通旋转填料床更具优势。

The rotating packed bed with split packing （SP-RPB） is a new efficient apparatus for chemical process intensification, which has an obvious enhancement on the mass transfer processes like distillation and absorb processes which restricted by gas phase mass-transfer resistance. Computational fluid dynamics （CFD） method was employed to simulate the gas flow in the SP-RPB, and the effects of fluid velocity, rotating speed and rotating form of the packing on internal pressure field, velocity field, and turbulent kinetic energy in the SP-RPB were investigated. RNG k-~ turbulent model and SIMPLE algorithm were used in the calculation, and packing layer was modeled by Porous Media model, the simulation results and experimental data are fitted well. The results indicate that the gas-phase pressure drop mainly comes from the packing area, tangential velocity far outweighs the radial velocity, rotating field plays a major role in the flow field, and it has a higher turbulent extent and more evenly distribution of the turbulent kinetic energy along the radial of packing in SP- RPB than ordinary rotating packed beds, which also shows that SP-RPB is particularly suitable for intensification of gas phase mass transfer processes.